Escapement mechanism



July 7, 1925.

A. B. ELY

ESCAPEMENT MECHANI SM Filed April 9, 1923 2SheetsSheet 1 IN VENTOR 146071305. /8

- A TTORNE Y5 July 7, 1925.

1,544,567 B. ELY

ESCAPEMENT MECHANISM Filed April 9. I925 2 Sheeis-Sheet 2 IN VEN TOR Ala/1505.59

A TTORNE Y5 To all whom it may concern:

Patented July 7, 1925.

:ALONZO B. ELY, OF GROTON, NEW YORK,

ASSIGNOR TO CORONA 'TYPEWRITER COM- PAN'Y, ING, OF GR-OTON, NEW YORK, A CORPORATION *OF NEW YORK. v

EsoArEMENr MECHANISM.

Application filed April 9, 1923. Serial No. 630,787.'

13c it'known that I, ALoNzo B. ELY, a citizen of the United States, and resident of Groton, in the-county ofTo-mpkins and State of New York, have invented certain new and useful Improvements in Escapement Mechanism, of which the following is a specification.v

This invention relates to improvements in escapement mechanism for traveling carriages of typewritingmachines, calculating machines, and the like, and has for its object to provide a carriage stepping mechanism which will operate without noise and without injurious shocks upon the operating parts. -A further object is to provide improved adjustable stopping means for the limber or stepping dog. Other features and advantages of the invention will hereinafter appear.

The improvements are illustrated in con nection with the well-known Corona typewriting machine, but are applicable to'other machines.

In the drawings, wherein the preferred embodiment of the invention is illustrated,

Figure 1 is an inverted plan view of the platen carriage and bed of a Corona typewriting machine equipped with the improved escapement mechanism, the parts being in normal position; 7

Fig. 2 an inverted plan view of the rocker, the stepping dog and its advancing means being shown in advanced position;

Fig. 3 a detail rear elevation, showing the stepping dog disengaged from the rack and advanced; 1 V Y Fig. 4 a view similar to Fig. 3 showing the normal position of the parts;

Fig. 5 a view similar to Fig. 4, showing the action of the parts when an abnormal shock or pressure is exerted on the loose or stepping dog by the rack in operation or handling of the machine; and

Fig. 6 a detail view showingthe parts of the'adjustable and yieldable stopping means for the stepping dog.

. Referring to the parts by numerals, 1

designates the platen carriage of the Corona machine which travels back and forth on the carriage bed 2 mounted on the folding frame bars 3 of said machine. The carriage 6 and urged in counterclockwise direction by the usual coiled motor spring 7'. The escapement 'i'ack 8 is rigidly held to the under side of" the carriage between the .carriage and bed. The dog rocker 9 extends transversely of the machine under the bed 2and is pivotally held at its left-hand end to the bed by means of pivot screw 10 to rock horizontally transversely of rack 8.

The free end of the rocker is normallyurged forwardly by aspring llconnectin'g an arm 12 of the rocker with a bracket 13 on the bed, said forward movement of the rocker being arrested by the engagement of afinger 14; on the rocker with a bracket 15 011 the bed." The rocker is moved rearwardly by a tappet (not shown) which presses against the'forward edge of arm 33 of the rocker when a type key or the space bar of the machine is' depressed.

WVhen the rocker is in normal position. the loose or stepping dog 16 is in engagement with a 'toothofthe rack 8 and is rocked toward the left under pull of carriage motor spring 7v against the tension ofits advancing spring [17." Spring 17 connects the rearwardly extending arm of a bell-crank dogadvancing lever 18 with the dog rocker and normally urges said arm of lever 18 toward the leftto swing the nose of 'dog' 16 toward the right through engagement of said lever the rocker by a vertical pivot screw 22 and. its transverse armbeing normally held away from stop '21 by the pressure of tail-piece 16 of the loose dog under the influence of the carriage s'pring 7. Tail piece 16 of dog 16 is normally pulled toward the right against advancing lever 18 by a coil spring 23 which is weaker than spring 17 and serves to permit do g'16t0 yield as the rack moves toward the right during return movements of the carriage and restore the dog to normal position after a'rack tooth passes thereover. Stop 21 limits the advance movement of dog 16 by spring 17 and lever 18 when the dog is released from the rack. The dogs extend through an opening 34 in the carriage bed.

In the Corona machine a stop arm 24 on dog 16 engages a rigid stop on the rocker. I have provided improved stop means for cooperation with arm 24 and have provided said arm with a depending finger 24 for the purpose hereinafter described. I have also provided cushioning and noise-eliminating means in connection with stop 21 and lever 18, hereinafter described. Except as just explained the parts above described are constructed as in the Corona machine, and the improvements will be 110w described in detail.

Lever 18 is pivoted on the enlarged shank portion 25 of screw 22 and one end of a flat or leaf spring 27 is tightly clamped between shoulder 26 on said screw and the under face of dog rocker 19. The spring 27 is preferably bowed slightly as shown and its free end normally abuts against the under face of the rocker and underlies arm 24 of dog 16. An adjustable stop screw 28 is screwed through a threaded aperture 29 in the free end of sprin 27 and is held in adjusted position by a lock nut 30 threaded thereon and engaging under the spring.

The upper end of the stop screw 28 extends loosely through an opening 31 in the dog rocker andprojects above said rocker and normally engages under arm 24 inside of finger 24 toarrest dog 16 in the position shown in Fig. 4. Spring 27 is as strong as or slightly stronger than carriage motor spring 7 so that when arm 24 strikes stop 28 at the end of the drop or feed movement of the carriage spring 27 and stop 28 will yield slightly to a position intermediate the positions shown in Figs. 4 and 5 but will instantly return to the normal position shown in Fig. 4. The shock will thus be cushioned and noise eliminated by the improved stop means but the proper relation of dogs 16 and 20 will be maintained. Screw 28 preferably normally extends slightly diagonally upward as shown in Fig. 4 so that thrust of arm 24 will be exerted substantially directly axially of the screw at all times.

At times in the handling and operation of the machine very severe shocks or pressures are or may be exerted against the loose dog 16, which might flex spring 27 to such an. extent that said spring would remain permanently bent downward from the rocker. To prevent this I have provided the finger 24 on arm 24 which is designed to permit sufficient yielding of the dog for the purposes above described but will engage'the upper face of the rocker and positively arrest the dog before it can be swung far enough to permanently bend spring 27 or flex the same beyond its limit of elasticity.

The shock and noise incidental to engagement of lever 18 with stop 21 as dog 16 is stepped or advanced by spring 17 is eliminated by providing a bumper or pad of cushioning or sound-deadening material on the t 'ansverse arm of said lever, said bu1npor preferably consisting of a tube or sleeve 32 formed of rubber and frictionally held on said lever arm in position to engage stop 21. By screwing stop 28 up or down the normal relation of the dogs may be varied as desired to regulate the drop.

What I claim is:

1. In an escapement mechanisn, the combination of a spring-driven toothed member, feed and holding dogs, means for vibrating the dogs to position the same alternately for engagement with the toothed member, said means nornally positioning the feed dog for engagen'ient with the toothed member, and manually adjustable resiliently supported means for silently arresting the feed dog after movement of said dog by the toothed member and yieldably holding the feed dog in a predetermined relation with the holding dog against the pressure of said springdriven toothed member.

2. In an escapement mechanism, the combination of a feed spring, a toothed member constantly urged in one direction by said feed spring, a pivoted stepping dog normally engaged with said toothed member, a holding dog normally disengaged from said toothed vmember, a dog-carrier for moving the dogs alternately into engagement with the toothed member, a stop adapted to be engaged by the stepping dog to limit pivotal movement there-of under pressure of the spring-urged toothed member, and a normally non-flexed leaf spring supportingsaid stop adapted to yield momentarily under impact of the pivoted dog, said spring being of sufficient strength to return to normal nonfiexed position and hold the stepping dog in predetermined re lation to the holding dog against the pressure of the feed spring when the momentum of the toothed member is spent.

3. In an escapementmechanism, the combination of a feed spring, a toothed member urged in one direction by said feed spring, holding and feed dogs, means for moving the dogs alterately into position for engagement with the toothed member, said means normally positioning the feed dog for engagement with the toothed memher. a yieldable stop device into engagement with which the feed dog is adapted to be urged by the feed spring and toothed member, and spring means for moving the feed dog away from the stop device when said dog is freed from the toothed member, said yieldable stop device being constructed to yieldingly resist movement of the feed dog said member, a pivoted feed dog normally when engaged thereby and to restore said dog to a point determined by the'normal set position of said stop device after any yielding movement of the device under feed shocks or excessive pressure transmitted to the feed dog. v

4-. In an escapement mechanism, the combination of a feed spring, a toothedsmember normally urged in one direction by the feed spring, a vibratory dogcarrier, a holding dog, a pivoted feed dog, said dogs being mounted on the carrierfor movement thereby transversely ofthe toothed member, a'

leaf springsecured at one end to the dog carrie and provided with a screw-threaded aperture adjacent its free end, an adjustable stop screw threaded through said aperture and having'one end inposition to be engaged by the feed dog when said dog is rocked about its. pivot by the spring-urged toothed member, and spring means for swinging the feed dog vabout its pivot away from said-stop. 1 i

5. In an esoapement mechanism, the combination of a feed spring, a toothed member normally urged inone direction by the feed spring, a vibratory dog carrier, a holding dog, a pivoted feed dog, said dogs being mounted on the carrier for movement thereby transversely of the toothed member, a'leaf sprin secured at one end to the dog carrier and provided with a screw-threaded apertnre adjacent its free end, an adjustable stop screw threaded through said aperture and having one end in position to be engaged by the feed dog when said dog is rocked about,

its pivot by the spring-urged toothed member, and spring means for swinging the feed-dog about its pivot away from said stop, said leafspring being at least as strong as the feed spring.

,6. In an escapement mechanism, the combination of a feed spring, a. toothed memberj normally urged in one direction by the feed spring, a vibratory d-og carrier, aholding dog, a pivoted feed dog, said dogs being mounted on the carrier for movement thereby transversely of the toothed member, a leaf spring secured at one end to the dog carrier and provided with a screw-threaded aperture adjacent its free end, an adjustable stop screwthreaded through said aperture and having one end in position to be engaged by the feed dog when said dog is, rocked about its pivot by the spring-urged toothed men ber, spring means for swinging the feed dog about its pivot away from said stop, said leaf spring being at least as strong as the" amount of flexure of the leaf spring.

7. In an. escapement mechanism, the comfecd spring. and means for limiting the bination of afeed spring,- a toothed member normally urged in one direction by said feed spring, a holding dog'normally free from engaged with said member,-a pivoted dog rocker for rocking the dogs to position first one and then the other dog for engagement 'ith said member, 'a leaf spring secured at one end to, the dog rocker and normally engaging the rockeriat'its, free end, a stop carried by the free end of the spring,-a stop bein of sufficient stren th toreturn to nor mal position when opposed'solely by force exerted by thefeed spring, and means for urging the feeddog about-its pivot away from said stop when the feed dog is freed fromthe toothed memben Y 8. In an escapement mechanism, the combination of a feed spring, a toothed member constantly urged in one direction by the feed spring, a holding dog, a-pivoted feed dog, adog rocker upon which the dogs are mounted, a leaf spring secured at one end to the dog rocker, a stop carried by the free end of the spring, a stop armon the feed dog adapted to engagesaid stoprto arrest the feedmovement of the feed dog, said leaf spring being as-strong as the feed spring and said arm having a projection adapted toengage the dog rocker to limit the flexure of the leaf spring, a lever pivotally held intermediate its endsto the dogrocker and having one arm engaging the feed dog, a dog-advancing spring connected with said lever and the dog rocker for swinging said lever infasdirection to rock, the feed dog away from its stop, a lever stop on the dog rocke'radapted tobe engaged by the other arm ofthe lever to limit the movement of the lever bythe dog-advancing spring, and an elastic bumper carried by said last-mew tioned lever arm adapted .to engage the lever t 9. In an escapement mechanism, the combination of adog rocker, a rigid dog at one faceofthe'rocker, a feed dog pivotally held to the rigid dog and having a tail piece extending beyond the. opposite face of the rocker, a feed-,dog-advancing lever located at said. opposite face of the rocker and having one 'arm engaging. the tail piece of the feed dog, a leaf spring located at said 0pposite face of the rocker with one end under said lever intermediate the ends of the lever,-

mediate its ends and clamping the adjacent end of theleaf spring against the rocker,

the free end of said leaf spring having a threaded aperture and the rocker having an opening registering with said threaded aperture, a stop screw threaded through the aperture in the leaf spring and projecting loosely through the opening in the rocker, a stoparm on the feed dog, a feed-dog-restoring spring connecting the tail piece of the feed dog with the rocker and normally urging the stop arm toward the projecting end of the stop screw, a dog-advancing spring stronger than the return spring connecting the lever with the rocker and normally urging the feed dog away from the stop screw, and a lever stop on the dog rocker cooperating with the other arm of the lever to limitmovement of the lever by the dog-advancing spring.

- 10. In an escapement mechanism, the combination of a dog rocker, a rigid dog at one face of the rocker, a feed dog pivotally held to the rigid dog and having a tail piece extending beyond the opposite face of the rocker, a feed-dog-advancing lever located at said opposite face of the rocker and hav; ing one arm engaging the tail piece of the feed dog, a leaf spring located at said opposite face of the rocker with one end under said lever intermediate the ends of the lever, a shouldered screw threaded into the rocker for pivotally supporting the lever intermediate its ends and clamping the adjacent end ofthe leaf spring against the rocker, thefree end of said leaf spring having a threaded aperture and the rocker having an opening registering with said threaded aperture, a stop screw threaded through the aperture in the leaf spring and projecting loosely through the opening in the rocker, a stop arm on the feed dog, a feed-dogrestoring spring connecting the tail piece of the feed dog with the rocker and normally urging the stop arm toward the projecting end of the stop screw, a dog-advancing spring stronger than the return spring connecting the lever with the rocker and normally urging the feed dog away from the stop screw, a lever stop on the dog rocker cooperating with the other arm of the lever to limit movement of the lever by the dog-advancing spring, and a rubber sleeve on said last-mentioned lever arm for engaging the lever stop.

11. In an escapement mechanism, the combination of a toothed member to be spaced, a feed dog movable parallel with the toothed member and normally engaged therewith, a holding dog normally disengaged from the toothed member, means for vibrating the dogs transversely of the toothed member, a feed spring for driving the toothed member in one direction, a spring weaker than the feed spring for urging the feed dog in the opposite direction when said dog is freed from the toothed member, a spring stop device for silently arresting movement of the feed dog by the feed spring and toothed member, and means for positively limiting movement of said device toward the dog to determine the normal position of the stop device and the normal point of arrest of the feed dog, said feed dog being moved out of contact with the stop device by said Weak spring, said spring stop device being positioned for engagement by the feed dog only after said dog has been moved by the feed spring to its normal point of arrest and yieldably opposing movement of said dog by the feed spring beyond said point with spring power at least equal to the power exerted against the dog by the feed spring.

12. In an escapement mechanism, the combination of a toothed member to be spaced, a feed dog movable parallel with the toothed member and normally engaged therewith, a holding dog normally disengaged from the toothed member, means for vibrating the dogs transversely of. the toothed member, a feed spring for driving the toothed member in one direction, a spring weaker than the feed spring for urging the feed dog in the opposite direction when said dog is freed from the toothed member, a spring stop device for silently arresting movement of the feed dog by the feed spring and toothed member, means'for positively limiting movement of said device toward the dog to determine the normal position of the stop device and the normal point of arrest of the feed dog, said feed dog being moved out of contact with the stop device by said weak spring, said spring stop device being positioned for engagement by the feed dog only after said dog has been moved by the feed spring to its normal point of arrest and yieldably opposing movement of said'dog by the feed spring beyond said point with spring power at least equal to the power exerted against the dog by the feed spring, and manually adjustable means for varying the normal point of arrest of the feed dog without varying the power of said spring stop device.

13. In an escapement mechanism, the combination of a toothed member to be spaced, a feed dog movable parallel with the toothed member and normally engaged therewith, a

'holding dog normally disengaged from the toothed member, means for vibrating the dogs transversely of the toothed member, a feed spring for driving the toothed member in one direction, a spring weaker than the feed spring for urging the feed dog in the opposite direction when said dog is freed from the toothed member, a spring stop de vice for silently arresting movement of the feed dog by the feed spring and toothed member, means for positively, limiting the movement of said device toward the dog to determine the normal position of the stop device and the normal point of arrest of the feed dog, said feed dog being moved out of contact with the stop device by said weak spring, said spring stop device being positioned for engagement by the feed dog only after said dog has been moved by the feed spring to its normal point of arrest and yieldably opposing movement of said dog by the feed spring beyond said point with spring power at least equal to the power exerted against the dog by the feed spring, and emergency stop means for positively limiting the extent of movement of the spring stop device by the feed dog when said dog is subjected to greater force than that exerted solely by the feed spring.

14:. In an escapement mechanism, the combination of a toothed member to be spaced, a feed dog movable parallel with the toothed member and normally engaged therewith, a holding dog normally disengaged from the toothed member, means for vibrating the dogs transversely of the toothed member, a feed spring for driving the toothed member in one direction,a spring weaker than the feed spring for urging the feed dog in the opposite direction when said dog is freed from the toothed member, a spring stop determine the-normal position of the stop dea vice and the normal point of arrest of the feed dog, said feed dog being moved out of contact with thestop device by said weak spring, said spring stop device being positioned for engagement by the feed dog only after said dog has been moved by the feed spring to its normal point of arrest and yieldably opposing movement of said dog by the feed spring beyond saidv point with spring power at least equal to the power exerted against the dog by the feed spring, emergency stop means for positively limiting the extent of movement of the spring stop device by the feed dog when said dog is subjected to greater force than that exerted solely by the feed spring, and manually adjustable means for varying the normal point of arrest of the feed dog.

In testimony whereof I hereunto aflix my signature.

ALONZO B. ELY. 

